A new approach for detecting pathogenic bacteria in platelet concentrates rapidly is proposed. Technically, the approach is based on an unconventional implementation of impedance sensing to monitor cellular metabolic responses with exceptional sensitivity and stability. This enables the detection of small numbers of viable aerobic and anaerobic microorganisms in near-real time without the need for grown cultures significantly reducing the time from sample collection to detection results by several days compared to currently in use methods. Feasibility of the approach was successfully demonstrated as part of the Phase I investigation with representative Gram-negative and Gram-positive species commonly implicated in platelet- associated bacterial sepsis. In addition, the ability to make decisive measurements in short time enables the bacterial testing of platelets just prior to transfusion ensuring the safety of the patient and potentially extending platelets shelf life. The proposed Phase II effort focuses on the development of a prototype instrument and testing of contaminated platelets in a realistic setting. The described approach may also be applicable to the detection of bacteria in other blood products. Bacterial contamination is detected in approximately one of every 2000 units of platelets and is implicated as the cause of severe or fatal sepsis in an estimated 150 patients per year in the United States. The proposed rapid test will enable the detection of viable contaminant bacteria in platelet supplies in near-real time both insuring their safe use and extending their useable life-span. [unreadable] [unreadable] [unreadable]